A vehicle is equipped with several illumination devices. For instance, an interior lamp to illuminate the vehicle interior, or a map lamp to illuminate each seat to aid the passenger to see a map, etc.
An illumination device for a vehicle is disclosed in Japanese Patent Laid-Open Publication No. 2006-123794 (Patent Literature 1) as an example of the illumination devices. The illumination device for a vehicle includes an illumination module extending in the front-and-rear direction on the ceiling of the vehicle. The illumination module has LEDs at the front end, middle section, and rear end thereof. In the illumination device, illumination light from the plurality of LEDs is condensed and emitted to a predetermined direction by a light condensing part comprising a plurality of condenser lenses.
Also, an illumination device is disclosed in Japanese Patent Laid-Open Publication No. 2011-173437 (Patent Literature 2). This illumination device includes a map-lamp unit provided on the ceiling of the vehicle and uses a condenser lens to illuminate a predetermined area by illumination light emitted from LED light sources disposed in the map lamp unit.